This invention relates to a connector in which a front holder is attached to a front end of a housing, receiving connection terminals therein, to cover distal ends (front ends) of the connection terminals.
Air bag devices have heretofore been used to protect automobile passengers from the impact of a collision. For inflating an air bag of the air bag device, an inflator of the air bag device is energized. When the inflator is energized, a propellant, contained in this inflator, is explosively burned, and expansion gas, produced as a result of this combustion, is introduced into the folded air bag to instantaneously inflate or expand the air bag.
A plurality of current-supplying wires extend outwardly from the inflator, and the inflator is electrically connected via these wires to a clock spring. A power source-side drive control unit for driving and controlling the inflator is electrically connected to the clock spring. When a potential difference due to electromagnetic waves or static electricity develops between the wires before the connection of the inflator, there is a possibility that the inflator malfunctions to cause the air bag to be inflated. Therefore, usually, short-circuiting resilient contacts (that is, short-circuiting springs) are contained in a connector provided at the distal end portions of the wires, each short-circuiting resilient contacts serving to short-circuit the mating connection terminals (secured respectively to the distal ends of the wires) together.
FIGS. 6 to 10 show one example of connectors containing the above-mentioned short-circuiting resilient contacts.
As shown in FIGS. 6 to 8, a plurality of terminal chambers 2a, separated from one another by partition walls 2h, are arranged in a row within a housing 2 of the connector 1. The connection terminals 3 (each having a wire W connected to a rear end thereof) for connecting an inflator and others to a power source are inserted respectively into the terminal chambers 2a through a rear end of the housing 2 in a direction of arrow A, and are received in these terminal chambers 2a, respectively.
The lance (that is, an elastic retainer) 2b, having its distal end portion projected into the terminal chamber 2a in the housing 2, is engaged in an engagement hole 3a formed in the connection terminal 3. Therefore, the connection terminal 3 is retained against withdrawal from the housing 2. The retaining member (that is, a spacer) 6 for retaining the connection terminals 3 in a double locking manner is inserted in a direction of arrow E into a recessed portion 2c formed in the housing 2. In this inserting operation, a distal end 6a of the retaining member 6 is engaged in engagement recesses 3b formed respectively in the connection terminals 3, thereby fixing the connection terminals 3 in a double locking manner within the housing 2.
A space 2d is formed in the housing 2, and is disposed below the terminal chambers 2a, and communicates with the terminal chambers 2a, and the short-circuiting resilient contacts 8 are received in the space 2d, and each short-circuiting resilient contact 8 contacts both of the pair of corresponding connection terminals 3 to short-circuit them together. The short-circuiting resilient contact 8 is formed by bending a metal sheet so as to have a roughly oval cross-sectional shape, and to have a pair of contact plate portions 8a. The pair of contact plate portions 8a, received in the space 2d, project respectively into the corresponding terminal chambers 2a, and contact the pair of connection terminals 3, respectively, to short-circuit them together.
As a result, there develops no potential difference between the pair of connection terminals 3, and therefore even if current due to electromagnetic waves or static electricity flows through the wires W when mounting an air bag device on a vehicle body of a vehicle, the air bag device (particularly the inflator) is prevented from malfunction. Mating connection terminals (not shown) and insulating plates (not shown) are provided in a power source-side mating connector (not shown) in which the connector 1 is adapted to be fitted. When the connector 1 is fitted in the mating connector, the connection terminals 3 are connected to the mating terminals, respectively, and at the same time the insulating plate is inserted between the connection terminal 3 and the short-circuiting resilient contact 8, thereby eliminating the short-circuiting effect by the short-circuiting resilient contact 8.
Generally, in an integrally-molded connector, the positional relation between terminal chambers and lances in a housing is such that each terminal chamber and the corresponding lance are spaced from each other in an upward-downward direction when viewed from the front or the side of the connector so that molds can be withdrawn from the molded housing. More specifically, terminal insertion ports (into which connection terminals of a mating connector are inserted, respectively) in a front wall of the housing and the lances are arranged such that each terminal insertion port does not overlap the corresponding lance in the upward-downward direction when viewed from the front side of the connector. With this arrangement, the ordinary connector is of such a construction that the front wall of the housing will not interfere with a mold for molding the lances when withdrawing this mold.
However, in order to meet a demand for a compact design of connectors in recent years, there has been proposed the type of connector in which a connector housing is divided into two separate parts, that is, a housing and a front holder, taking into consideration the withdrawing of a mold from the molded connector. The two parts are molded separately from each other, and thereafter are assembled together. One such example is the connector shown in FIGS. 6 to 10. Although a front wall 4b of the front holder 4 is disposed in overlapping relation to the lances 2b in the upward-downward direction as shown in FIG. 7, the front wall 4b of the front holder 4 will not interfere with the withdrawing of the mold since the front holder 4 and the housing 2 are separate from each other, and therefore the mold can be suitably designed. As a result, the dimension of the connector 1 in the upward-downward direction is reduced, so that the compact design of the connector 1 is achieved.
A plurality of terminal insertion ports 4a are formed in the front holder 4 as shown in FIG. 6, and when the connector 1 is fitted into the mating connector, the mating connection terminals (male connection terminals) are inserted into these terminal insertion ports 4a, respectively. As shown in FIGS. 9A to 9C, retaining projections 4d are formed on opposite side walls 4c of the front holder 4, respectively. Each retaining projection 4d is of a generally trapezoidal having slope faces 4f formed respectively at upper and lower portions thereof.
The housing 2 is formed by injection molding a synthetic resin in such a manner that a recessed space is formed at its front end portion. The recessed space is defined by opposite side walls 2e and a lower wall 2f interconnecting the opposite side walls 2e. As shown in FIGS. 6 and 10, engagement holes 2g are formed in the opposite side walls 2e, respectively. When the front holder 4 is inserted and fitted into the recessed space of the housing 2 in a direction of arrow B (see FIG. 7), the retaining projections 4d of the front holder 4 are engaged in the engagement holes 2g, respectively. As a result, the front holder 4 is fixed to the housing 2.
In the related-art connector 1, however, the front holder 4 is molded into such a shape that the height of the widthwise side portions of the front holder 4 is large (thick) while the height of the widthwise central portion is small (thin) as shown in FIG. 9A. Therefore, a pressing force, applied from the short-circuiting contact piece 8, acts on the front holder 4 through the connection terminals 3, and the widthwise central portion of the front holder 4 is urged in a direction of arrow C, and is deformed by creep into an arcuate shape.
And besides, when the force, acting in the direction (that is, in the direction of arrow C) to cancel the engagement of the front holder 4 with the housing 2, exceeds the force of engagement of the front holder 4 with the housing 2, the retaining projections 4d of the front holder 4 are disengaged respectively from the engagement holes 2g of the housing 2, which leads to an anxiety that the front holder 4 is disengaged from the housing 2.
It is therefore an object of the invention is to provide a connector which is compact in size, and is reliable such that a housing and a front holder can be positively kept engaged with each other.
In order to achieve the above object, according to the invention, there is provided a connector, comprising:
a housing body, comprising:
a partition wall for defining a plurality of chambers adapted to accommodate terminals which are inserted from a rear end portion of the housing body, the partition wall being formed with a recessed part; and
a pair of opposite side walls and a bottom wall interconnecting the side walls, for defining a recessed space at a front end portion of the housing body such that front ends of the terminals accommodated in the chambers are exposed therefrom, each of the side walls being formed with a recessed part; and
a front holder, fitted into the recessed space in a first direction to cover the exposed front ends of the terminals, the front holder comprising:
a pair of first projections, each of which is formed with a first flat face facing in a second direction opposite to the first direction and extending in a third direction perpendicular to the second direction, and is adapted to be engaged with the recessed part of each of the side walls of the housing body; and
a second projection, formed with a second flat face facing in the second direction and extending in the third direction, and is adapted to be engaged with the recessed part of the partition wall of the housing body.
In such a configuration, the front holder fitted into the recessed space is retained therein by the first projections and the second projection. Accordingly, the front holder can be firmly engaged with the housing body.
Further, since the first and second faces extend in the direction perpendicular to the direction in which the front holder is detached from the recessed space. Accordingly, even if force for detaching the front holder from the recessed space is act on the front holder, such force can be received by the first and second flat faces engaged with the recess portions of the housing body. Therefore, the inadvertent disengagement between the housing body and the front holder can be avoided.
Preferably, a center portion of the front holder in a direction that the chambers are arranged is reinforced by increasing a dimension in the first direction.
In such a configuration, the front holder is less liable to be bent, and the amount of deformation of the front holder due to a temperature change and so on is reduced. Therefore, this is no anxiety that the front holder is disengaged from the housing body as a result of deformation of the front holder.